Newsgroups: comp.sys.amiga.hardware
Path: utzoo!censor!comspec!darrell
From: darrell@comspec.uucp (Darrell Grainger)
Subject: Re: GVP Tape Backup Unit
Organization: Comspec Communications Inc., Toronto Ontario Canada
Date: Thu, 14 Feb 91 14:29:17 GMT
Message-ID: <1991Feb14.142917.9746@comspec.uucp>
Summary: SCSI controllers
	 GVP != Xetec
References: <1484@richsun.cpg.trs.reuter.com>

In article <1484@richsun.cpg.trs.reuter.com>, boi@richsun.cpg.trs.reuter.com (Ken Boi) writes:
> I own a Xetec Fastrack hard drive controller board. I recently 
> purchased a GVP 105Mb streamer tape backup unit. The tape unit
> has been set up to plug into the SCSI extension port on my 
> Xetec controller. Unfortunately, the GVP backup software does
> not recognize the tape units existence. Now I am told (contrary
> to the purchase statements) that the GVP tape unit will not
> work with the Xetec controller, and that I should replace my 
> controller with a GVP unit. I guess I am confused. Shouldn't 
> this tape unit just be treated as another SCSI device? Aren't 
> there some SCSI standards which all controllers and attached 
> devices should adhere to, thereby allowing this unit to work 
> with my current controller setup?
> 
> One other question, if I do need to replace the controller,
> will I need to reformat my entire harddrive? Thanks.

 The SCSI standard just determines how the controller card communicates with
the hard drive/tape streamer. It does not have to be the same from the SCSI
controller to the computer. Each SCSI controller has ROMs that map themselves
into memory. The software that comes with the controller knows how to find
those ROMs and which routines are where (relative to the start of the ROM).

 Since the GVP software will not work with your Xetec controller you will
either have to get software from Xetec that does the same thing as the GVP
software would do or you are going to have to get a GVP controller to go
with the software. If you switch to a GVP controller you will have to backup
and reformat you SCSI hardware. 

 I have not looked at the RKM (ROM Kernal Manuals) for Libs & Devs recently
but I do remember there are some SCSI routines listed. My guess would be that
the routines provided by Commodore were deemed unsatisfactory (to slow or
something) so the other companies formed their own method of using SCSI devices.
 
 Darrell


